Tartrate of potash and soda indicate, under these circumstances, only the presence of cinchonidine.
Red bark contains not only quinine and cinchonine, but also cinchonidine.
Dr de Vrij states that the substance known under this name is a mixture of hydrochlorate of cinchonidine and of cinchonine.
cinchonidine, when heated with potassium hydrate, yields quinoline also, and with nitric acid the same products as cinchonine.
If it is chemically pure, cinchonidine belongs to the non-fluorescent alkaloids.
It is nothing more than quinidine, or cinchonidine, or a mixture of both.